title: Endoscopic ultrasound staging is adversely affected by placement of a self-expandable metal stent: fact or fiction?
abstract: OBJECTIVE
  Accurate preoperative staging of pancreatic cancer (Pca) is crucial to direct management. There is a perception that endoscopic ultrasound (EUS) staging should be performed before biliary decompression because of artifact caused by self-expandable metal stents (SEMS). Our aim is to determine whether placement of SEMS affects the staging of Pca.
  
  
  METHODS
  Fifty-five patients (35 men; mean age, 67 years) with newly diagnosed Pca staged in the last 5 years and captured prospectively were divided into 2 groups matched by age, sex, and final staging. The staging accuracy of EUS in patients who had a SEMS (n = 28) was compared with patients without a SEMS (n = 27). The gold standard was surgical pathology, or cytologic confirmation of metastatic disease. Multivariate analysis was effected on age, sex, presence of SEMS, and presence of metastasis to assess prediction of staging inaccuracy.
  
  
  RESULTS
  Endoscopic ultrasound correctly staged 14 (52%) of 27 patients in the no-SEMS group and 13 (46%) of 28 in the SEMS group. Logistic regression analysis identified only metastasis as a predictor of inaccuracy in EUS staging.
  
  
  CONCLUSIONS
  Endoscopic ultrasound staging of Pca does not seem to be affected by the presence of a SEMS. The major reason for misstaging in both groups was failure to detect metastatic disease.
authors.affiliation: Digestive Health Center, University of Virginia Health System, Charlottesville, VA 22908-0708, USA.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Shami
authors.forename: Anshu
authors.initials: A
authors.lastname: Mahajan
authors.forename: Vinay
authors.initials: V
authors.lastname: Sundaram
authors.forename: Eric M
authors.initials: EM
authors.lastname: Davis
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Loch
authors.forename: Michel
authors.initials: M
authors.lastname: Kahaleh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001662:Biliary Tract Surgical Procedures / Q000295:instrumentation*; D016022:Case-Control Studies; D003951:Diagnostic Errors / Q000517:prevention & control; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D015607:Stents
chemical_list: D008670:Metals